1. Field of the Invention
The invention relates to a mechanism for controlling a valve actuated by a camshaft and more specifically to a mechanism to vary the amount of opening and/or timing of cam actuated valves.
2. Description of the Prior Art
It is well known in the internal combustion engine art that a more flexible control of the engine valves will provide improved power and economy at virtually all engine speeds and loads. One method of providing more flexible valve control is taught in U.S. Pat. Nos. 2,934,052 and 3,277,874. Therein the camshafts are provided with high and low lift lobes for actuating each of the engine valves and means selectively operative to shift from valve actuation by one of the lobes to valve actuation by other of the lobes for varying the amount of valve opening and/or valve timing in accordance with engine operating conditions. It is also well known in the internal combustion engine art that improved operating economy may be obtained by disabling the valves of selected cylinders during certain engine operating conditions, for example, when the engine is lightly loaded. Another method of providing more flexible valve control is concerned with the concept of completely disabling selected valves when the engine is lightly loaded. Prior U.S. patent art is replete with patents teaching valve disablement.